CVE-2023-45819 — tinymce
MEDIUMCVE-2023-45819 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in tinymce. A fix is available for tinymce — see the affected versions and patch details below.
Cross-site Scripting vulnerability in TinyMCE notificationManager.open API
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-45819.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-45819 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
tinymcenpmDescription
TinyMCE is an open source rich text editor. A cross-site scripting (XSS) vulnerability was discovered in TinyMCE’s Notification Manager API. The vulnerability exploits TinyMCE's unfiltered notification system, which is used in error handling. The conditions for this exploit requires carefully crafted malicious content to have been inserted into the editor and a notification to have been triggered. When a notification was opened, the HTML within the text argument was displayed unfiltered in the notification. The vulnerability allowed arbitrary JavaScript execution when an notification presented in the TinyMCE UI for the current user. This issue could also be exploited by any integration which uses a TinyMCE notification to display unfiltered HTML content. This vulnerability has been patched in TinyMCE 5.10.8 and TinyMCE 6.7.1 by ensuring that the HTML displayed in the notification is sanitized, preventing the exploit. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | tinymce | ≥ 6.0.0&&< 6.7.1 | 6.7.1npm install tinymce@6.7.1 |
| 📦npm | tinymce | all versions | 5.10.8npm install tinymce@5.10.8 |
| .NETNuGet | TinyMCE | ≥ 6.0.0&&< 6.7.1 | 6.7.1dotnet add package TinyMCE --version 6.7.1 |
| .NETNuGet | TinyMCE | all versions | 5.10.8dotnet add package TinyMCE --version 5.10.8 |
| 🐘Packagist | tinymce/tinymce | ≥ 6.0.0&&< 6.7.1 | 6.7.1composer require tinymce/tinymce:^6.7.1 |
| 🐘Packagist | tinymce/tinymce | all versions | 5.10.8composer require tinymce/tinymce:^5.10.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tinymce, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tinymce to 6.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-45819 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-45819 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-45819. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-45819 in your dependencies?
O3 Security finds CVE-2023-45819 across npm, NuGet, Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.